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1.
A new record ponyfish, Deveximentum megalolepis Mochizuki and Hayashi, 1989, was documented based on its morphological characteristics and DNA barcode. Fifty specimens were collected from Beibu Gulf of China and identified as D. megalolepis by morphological characterization. The coloration, meristic traits, and morphometric measurements were consistent with previously published records. In general, it is a silver-white, laterally compressed and deep bodied ponyfish with 6–9 rows of scales on cheek; scale rows above lateral line 6–8; scale rows below lateral line 14–17. Mitochondrial cytochrome oxidase I subunit (COI) gene fragment was sequenced for phylogenetic analysis. There is no sequence variation of COI gene between the specimens collected in this study. The genetic distances between D. megalolepis and other congeneric species range from 3.6% to 14.0%, which were greater than the threshold for fish species delimitation. The COI sequence analysis also supported the validity of D. megalolepis at genetic level. However, the genetic distance between Chinese and Philippine individuals was about 1.2% and they formed two lineages in gene tree, which may be caused by the geographical distance.  相似文献   

2.
A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial (COI, Cyt b and control region) and nuclear (5S rDNA) DNA sequence data in multigene perspective. A variety of phylogenetic analytic methods were used to clarify the current taxonomic Classification and to assess phylogenetic relationships and the evolutionary history of this genus. The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber. We confirmed that S. japonicus and S. colias were genetically distinct. Although morphologically and ecologically similar to S. colias, the molecular data showed that S. japonicus has a greater molecular affinity with S. australasicus, which conflicts with the traditional taxonomy. This phylogenetic pattern was corroborated by the mtDNA data, but incompletely by the nuclear DNA data. Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes Supports an Atlantic origin for Scomber. The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus. The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events. In addition, our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution, from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.  相似文献   

3.
Acila divaricata (Hinds, 1843) and A. mirabilis (Adams and Reeve, 1850) are common benthic bivalves in China. A number of researchers have proposed that the latter species is a junior synonym of the former species. Because of morphological similarities, it is difficult to distinguish these two species based on visual examination only. For better understanding of their taxonomy, the mitochondrial COI gene fragments of five individuals of A. divaricata from the East China Sea and six individuals of A. mirabilis from the Yellow Sea were sequenced in this study. The phylogenetic relationships of the obtained COI sequences, together with nineteen sequences of three species of the genus Nucula, were analyzed. The pairwise intra- and inter-specific distances for the COI sequences ranged from 0.002 to 0.017 and from 0.128 to 0.134, respectively, and no overlap was found. Phylogenetically, A. divaricata and A. mirabilis form distinct clades and cluster into a sister to all other Nucula species. The results indicated that A. divaricata and A. mirabilis are two distinct species. The differences in the morphology and distribution between the two species were briefly discussed.  相似文献   

4.
The systematic classification of the Eucheumatoideae is difficult because of their variable morphology and interpretation of reproductive structures. Kappaphycus and Eucheuma specimens cultivated on the Hainan and Fujian coast of China were introduced from Vietnam, the Philippines and Indonesia. Combined with morphological characteristics, all Kappaphycus and Eucheuma cultivated strains were identified by internal transcribed spacer (ITS) sequences. The phylogenetic tree was constructed using neighbor-joining and maximum likelihood methods. The results indicate that different ITS sequence lengths occurred in the different genera and species. An obvious difference in morphology could be found in the protuberance shape between Kappaphycus and Eucheuma. The protuberance in Eucheuma was thorn-like and in Kappaphycus was wartlike or papillate. Their ITS sequence lengths differed significantly in nucleotide variation rates up to 58.55%-63.90%. All nucleotide variations occurred in the ITS1 and ITS2 regions except for five nucleotide transversions in the 5.8S rDNA region. In addition, the difference was at the branches among congeneric species. Kappaphycus sp. had branches with small buds, while K. alvarezii did not have such a feature. The nucleotide variation rates varied from 7.02% to 7.48% among species; within the same species of the clades it was <1.20%. Eucheumatoideae algae cultivated in China consisted of three clades, K. alvarezii, Kappaphycus sp., and E. denticulatum. The results indicate that ITS sequence analysis was an effective way for identification of interspecies and intraspecies phylogenetic relationships and might provide a clue for molecular identification of algal Eucheumatoideae.  相似文献   

5.
1Introduction As part of a comprehensive investigation of ecosys-tem dynamics in the Yellow Sea and East China Sea,astudy has been made of meiofauna,defined here asmetazoans passing a0.5mm sieve but retained by a0.031mm sieve.Meiofauna is an important energeticgroup in benthic small food web due to their smallsize,high abundance and fast turnover rates.Theproduction of meiofauna is equal to or higher than thatof macrofauna in estuaries,shallow waters and deepseas(Gerlach,1971;Platt and Warw…  相似文献   

6.
Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of these organisms were tested against different fouling bacterial forms and II-instar stage of the barnacle, Balanus amphitrite. Antibiosis, bioactivity and followed by multivariate analyses were carried out to check the efficacy of antifouling effect of the selected marine organisms. Principal component analysis revealed the exemplary antifouling efficacy of the sponge extracts of Stylissa sp. observed followed by Hyrtios sp. against bacterial forms in the laboratory study. De-trended correspondence analysis confirmed that the contribution of antifouling efficacy of the selected sponge extracts was observed to be more towards Bacillus sp., Vibrio sp. and Alteromonas sp. Moreover, the efficacy of Hyrtios sp. extract(20.430 μg m L~(-1)) followed by Stylissa sp.(30.945 μg m L~(-1)) showed higher against barnacle instar compared with other extracts in the bioactivity assay. Bray-Curtis cluster analysis under paired linkage categorized all the sponge extracts into one major cluster with 75% similarity, and one outlier tunicate. More than 80% similarity observed between Hyrtios sp. and Stylissa sp. Fourier transform infrared spectroscopy(FTIR) showed that the contribution of major peaks found in the marine organisms were towards sulfones, sulfoxides, cyanates and ketones.  相似文献   

7.
The complete mitochondrial cytochrome oxidase subunit Ⅱ （COⅡ） gene of Penaeinae shrimp Fenneropenaeus chinensis was cloned and sequenced. The gene is 688 bp in length and codes for 229 amino acids. It shows 83.2%, 87.0% and 83.8% sequence similarity to Marsupenaeus Japonicus, Penaeus monodon and Farfantepenaeus notialis, respectively. The A＋T content of the whole gene and that at the third position of codons are 64.7% and 78.2%, respectively. The phylogenetic relationship between F. chinensis and three other species representing genera Farfanatepenaeus, Marsupenaeus and Penaeus was analyzed. Results showed that the genetic distances among the four taxa ranged from 0.144 0 to 0.200 5, exceeding those estimated with COⅠ and partial 16S rRNA gene sequences among Marsupenaeus, Litopenaeus and Melicertus, and being therefore larger than the value among subgenera. It has been suggested that the COⅡ gene has a faster evolutionary rate than that of the COⅠ gene and partial 16S rRNA gene and could be used for phylogenetic analysis at genus or species level. The results of the present study indicated that Farfantepenaeus, Fenneropenaeus, Marsupenaeus and Penaeus are at a higher phylogenetic level than subgenus, which supports the opinion of the elevation of phylogenetic status of the four subgenera to genus level.  相似文献   

8.
The genus Munidopsis has high biodiversity in seamount habitats.In this study,two new Munidopsis species,Munidopsis ahyongi sp.nov.and Munidopsis carolinensis sp.nov.from the Caroline Ridge in the tropical western Pacific Ocean were described.M.ahyongi sp.nov.is very similar to a group of species in the M.serricornis complex,but can be readily distinguished from the related species in having the oblique posterior orbital margins,2 spines on the lateral carapace margin,and a relatively longer rostral median spine.M.carolinensis sp.nov.is different from two related species primarily in having oblique frontal margins,blunt outer orbital angles,straight lateral margins of the rostrum,scale-like rugae on sternites 5-7,and less spinose pereopod 1(chelipeds,P1) merus and carpus.Aside from the morphological comparisons,DNA barcode analysis and phylogenetic analysis based on the cytochrome c oxidase subunit I gene(COI) were employed for the identification of these new species.  相似文献   

9.
The Andaman and Nicobar Islands are one of the Union Territories of India, located in the eastern part of the Bay of Bengal. In 2010 summer, the increment in sea surface water temperature (up to 34℃) resulted in the bleaching of about 74% to 77% of corals in the South Andaman. During this event, coral species such as Acropora cerealis, A. humilis, Montipora sp., Favia pallida, Diploastrea sp., Goniopora sp. Fungia concinna, Gardineroseries sp., Porites sp., Favites abdita and Lobophyllia robusta were severely affected. This study is to assess the recovery status of the reef ecosystem by estimating the percentage of Live Coral cover, Bleached coral cover, Dead coral with algae, Rubble, Sandy flat, Algal assemblage and other associated organisms. The sedimentation rate (mg cm-2 d-1) and coral coverage (%) were assessed during this study period. The average sedimentation rate was ranged between 0.27 and 0.89 mg cm-2 d-1 . The observed post bleaching recovery of coral cover was 21.1% at Port Blair Bay and 13.29% at Havelock Island. The mortality rate of coral cover due to this bleaching was estimated as 2.05% at Port Blair Bay and 9.82% at Havelock Island. Once the sea water temperature resumed back to the normal condition, most of the corals were found recovered.  相似文献   

10.
Genus Nassarius contains many subgenera, such as Zeuxis, Telasco, Niotha, Varicinassa, Plicarcularia, Nassarius s. str. and Reticunassa. On the basis of morphological characteristics of the shell and radula and sequences of mitochondrial cytochrome oxidase subunit I (COI) and 16S rRNA genes, Nassarius specimens collected from the South China Sea were identified and phylogenetically analyzed. Although Nassarius sp. and Nassarius (Varicinassa) variciferus were morphologically different in their shells, few variations were found among their radular teeth and sequences of mtCOI and mt16S RNA genes. Therefore, Nassarius sp. should be classified as N. (Varicinassa) variciferus. Nassarius (Zeuxis) sp. has only a subtle difference from Nassarius (Zeuxis) algidus on the shell, but it shows obvious differences in radular teeth and DNA sequence, indicating that they are two distinct species. Sequence divergence of mtCOI and mt16S RNA genes within Nassarius species was much lower than that between species, suggesting that these two genes are suitable for Nassarius species identification. Phylogenetic analysis (neighbor-joining and maximum parsimony) based on mtCOI and mt16S rRNA genes revealed the presence of two groups in genus Nassarius and a closest relationship between subgenera Zeuxis and Telasco. Species of subgenus Plicarcularia did not form a single clade. The molecular phylogeny was not congruent with the previous morphological phylogeny. The subgeneric divisions of genus Nassarius appear to be uncertain and unreliable.  相似文献   

11.
The high phenotypic plasticity in the shell of oysters presents a challenge during taxonomic and phylogenetie studies of these economically important bivalves. However, because DNA can exhibit marked differences among morphologically similar species, DNA barcoding offers a potential means for oyster identification. We analyzed the complete sequences of the cytochrome oxidase subunit I （COI） of five common Crassostrea species in China （including Hong Kong oyster C. hongkongensis, Jinjiang oyster C. ariakensis, Portuguese oyster C. angulata, Kumamoto oyster C. sikamea, and Pacific oyster C. gigas） and screened for distinct fragments. Using these distinct fragments on a high-resolution melting analysis platform, we developed an identification method that does not rely on species-specific PCR or fragment length polymorphism and is efficient, reliable, and easy to visualize. Using a single pair of primers （Oyster- COI-1）, we were able to successfully distinguish among the five oyster species. This new method provides a simple and powerful tool for the identification of oyster species.  相似文献   

12.
Grateloupia ramosa Wang & Luan sp. nov. (Halymeniaceae, Rhodophyta) is newly described from Hainan Province, southern China. The organism has the following morphological features: (1) purplish red, cartilaginous and lubricous thalli 5–10 cm in height; (2) compressed percurrent axes bearing abundant branches with opposite arrangement; (3) claw-like apices on top, constricted to 2–4 cm at the base; (4) cortex consisting of 3–6 layers of elliptical or anomalous cells and a medulla covered by compact medullary filaments; (5) reproductive structures distributed throughout the thallus, especially centralized at the bottom of the end portion of the branches; and (6) 4-celled Carpogonial branches and 3-celled auxiliary-cell branches, both of the Grateloupia-type. The morphological diff erences were supported by molecular phylogenetics based on ribulose-1, 5-bisphosphate carboxylase/oxygenase (rbcL) gene sequence analysis. There was only a 1 bp divergence between specimens collected from Wenchang and Lingshui of Hainan province. The new species was embedded in the large Grateloupia clade of the Halymeniaceae. The pairwise distances between G. ramosa and other species within Grateloupia ranged from 26 to 105 bp, within pairwise distances of 13–111 bp between species of the large genus Grateloupia in Halymeniaceae. Thus, we propose this new species as G. ramosa Wang & Luan sp. nov.  相似文献   

13.
The 5.8S ribosomal DNA sequences (5.8S rDNA) and their flanking regions, internal transcribed spacer 1 and spacer 2 (ITS1 and ITS2) of three new isolates in genus Alexandrium (Alexandrium sp. qd1, Alexandrium sp. qd2, Alexandrium sp. gz) from China were amplified, sequenced, and subjected to phylogenetic analysis. Alexandrium sp. gz and Alexandrium sp. qd1 were grouped with high bootstrap values with four strains/species, i.e., A. catenella South Korea strain, A. catenella Japan strain, and two from China, Alexandrium sp. AC03 and Alexandrium sp. AN01 being proposed to be A. catenalla in a previous study. Then Alexandrium sp. gz and Alexandrium sp. qd1 were identified as Alexandrium catenella. As A. catenella was isolated from Qingdao and Guangzhou sea areas, it supposedly distributed at least in these two areas and was genetically different. Alexandrium sp. qd2 differed greatly from species in Alexandrium. It clustered with Symbiodinium californium, Symbiodinium sp. G15 and Gymnodinium sp. Zhao 01 with 100% bootstrap value; so Alexandrium sp. qd2 affiliates to genus Symbiodinium, and is probably a free-living Symbiodinium species.  相似文献   

14.
Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal micro-communities involved in the biodegradation of Enteromorpha polysaccharides (EP) were seldom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL?1 in 32 hours. With denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading micro- community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.  相似文献   

15.
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16.
The phylogenetic relationship among Chinese Parapenaeopsis species was studied by comparing 16S rDNA and COI gene sequence. The results showed that Parapenaeopsis hardwickii (Miers, 1878) and P. cultrirostris Alcock, 1906 identified from Chinese samples were the same species. Parapenaeopsis cornuta (Kishinouye, 1900), P. incisa Liu and Wang, 1987, and P. sinica Liu and Wang, 1987 were different species. However, their systematic relationship were closer than those of other species, and they formed an advanced branch in the phylogenetic trees. Additionally, the systematic position of P. hardwickii (Miers, 1878), P. hungerfordi Alcock, 1905, and P. tenella (Bate, 1888) were not stable in the phylogenetic trees. More genetic markers such as 18S rDNA and 28S rDNA were supposed to be used to confirm the phylogenic relationship of Parapenaeopsis species.  相似文献   

17.
During an expedition to a seamount at Caroline Plate in the tropical Western Pacific,a new species of Tritonia was sampled from the upper bathyal zone at depth of 970-1 262 m.This new species,Tritonia iocasica sp.nov.,represents the first tritoniid nudibranch known to feed on octocoral of the family Melithaeidae.The species is up to 120 mm in length,pinkish in color;with the rhinophoral sheath divided into several petaliform extensions;veil with,about 18 elongate digitiform processes;notal margin with17-19 pairs of secondary gills;anus located below the 5~(th) and 6~(th) secondary gills,and the genitalia below the 3~(rd) secondary gill on the right side of the body.Based on these external features,T.iocasica sp.nov.can be dearly distinguished from all previously described members of the genus.Phylogenetic analyses of two mitochondrial(COI,16 S rRNA) and a nuclear(H3) genes using Bayesian inference,maximum likelihood,and species delimitation analysis also support the separation of T.iocasica sp.nov.from its congeners.  相似文献   

18.
Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I （COl） gene. A total of 76 specimens were collected from three localities around the East （Qidong and Zhoushan） and South China Seas （Zhuhai）. Among these individuals, nine polymorphic sites were detected and 1 l distinct haplotypes were defined. High levels ofhaplotype diversity （h=0.759i0.035） and low levels of nucleotide diversity （re=0.001 98i0.003 26） were observed in these populations, Hierarchical analysis of molecular variance （AMOVA） indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant （~0~t=0.032 85, P〈0.01）. These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.  相似文献   

19.
Japanese flounder is one of the most important commercial species in China; however, information on the genetic background of natural populations in China seas is scarce. The lack of genetic data has hampered fishery management and aquaculture development programs for this species. In the present study, we have analyzed the genetic diversity in natural populations of Japanese flounder sampled from the Yellow Sea (Qingdao population, QD) and East China Sea (Zhoushan population, ZS) using 10 polymorphic microsatellite loci and cytochrome c oxidase subunit I (COI) sequencing data. A total of 68 different alleles were observed over 10 microsatellite loci. The total number of alleles per locus ranged from 2 to 9, and the number of genotypes per locus ranged from 3 to 45. The observed heterozygosity and expected heterozygosity in QD were 0.733 and 0.779, respectively, and in ZS the heterozygosity values were 0.708 and 0.783, respectively. Significant departures from Hardy-Weinberg equilibrium were observed in 7 of the 10 microsatellite loci in each of the two populations. The COI sequencing analysis revealed 25 polymorphic sites and 15 haplotypes in the two populations. The haplotype diversity and nucleotide diversity in the QD population were 0.746±0.072 8 and 0.003 34±0.001 03 respectively, and in ZS population the genetic diversity values were 0.712±0.047 0 and 0.003 18±0.000 49, respectively. The microsatellite data (F_st =0.048 7, P<0.001) and mitochondrial DNA data (F_st =0.128, P<0.001) both revealed significant genetic differentiation between the two populations. The information on the genetic variation and differentiation in Japanese flounder obtained in this study could be used to set up suitable guidelines for the management and conservation of this species, as well as for managing artificial selection programs. In future studies, more geographically diverse stocks should be used to obtain a deeper understanding of the population structure of Japanese flounder in the China seas and adjacent regions.  相似文献   

20.
A crude protease produced from Planomicrobium sp. L-2 is described, and its effectiveness as an additive in liquid detergent evaluated. We isolate the protease-producing Planomicrobium sp. L-2 from the gastrointestinal tract of Octopus variabilis. At least three caseinolytic protease clear bands were observed in zymogram analysis. The crude alkaline protease was highly tolerant of a pH range from 7.0 to 9.0, and temperatures to 50°C after incubation for 1 h. Proteolytic enzymes were stable towards three surfactants (5% Tween 80, 1% Triton X-100 and 0.05% SDS) and an oxidizing agent (1% hydrogen peroxide), in addition to being highly stable and compatible with popular commercial laundry powered detergent brands available in China. Our study demonstrates the potential these proteases have for development into novel classes of detergent additive. This study also suggests that the gastrointestinal tract of Octopus variabilis may be a rich source of commercially valuable strains of enzyme.  相似文献   

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